Data Flow chart and business flow chart

When I started to build a data center charging system, master and I said that we had to analyze the requirements before doing the system. Only by clarifying the requirements can we start the project. So let's look at it first, but I haven't seen it for a long time. Later, master said that the first part of the data room charging system is the database. This makes me even more confused. I don't even know how the database can be created, because I don't know how the information flows. In addition, I always think that with the development going deeper, the database will not always be suitable. In this way, one change will be a piece. So, at last, I develop and get the database.

Later, when I read my self-examination book "Development and management of information systems", I learned the business flow chart and data flow diagram and found that I did not understand the analysis. Looking at the charging system of the IDC room, you cannot understand the business process of the entire system, that is, the demand and information flow. So, this blog will talk about the data flow chart first!

1) definition of data flow diagram (DFD, data flow digoal)

The system data flow chart can be drawn through surveys. A data flow chart is a main tool that comprehensively describes the logic model of an information system. It can use a few symbols to comprehensively reflect the flow, processing, and storage of information in the system.

2) Data Flow Chart features

Abstraction

In the data flowchart, the specific organization, workplace, personnel, and material flows have been removed, leaving only the data storage, flow, processing, and usage. This abstraction can summarize the Internal Rules of information processing.

General

It associates the system's processing processes for various businesses to form a general structure. However, the business flow chart can only analyze each business in an isolated manner and cannot reflect the Data Relationship between each business.

The role of the data flow chart:

1. system analysts use this tool to analyze the system information process from top to bottom.

2. You can plot the computer processing part on the graph.

3. Based on logical storage and further data analysis, You Can overdesign the database.

4. determine the access method based on the data flow

5. corresponding to a processing process, the corresponding programming language can be used to express the processing method, and the process is overdesigned to the program.

I know so much about it for the time being, but I still don't know much about other things. I will use it later. I will write new ideas!